Water-soluble immunological adjuvants, in particular for vaccines, obtained from mycobacteria and related microorganisms and process for their extraction

Abstract

The invention pertains to a water-soluble immunological adjuvant, especially for vaccines. It is obtained by enzymatic treatment of mycobacteria or Nocardia whole cells in aqueous medium and by a recovery from said aqueous medium.

We claim: 
     
       1. In the process for preparing a water-soluble immunological non-specific adjuvant which comprises treating an aqueous suspension of solvent-extracted delipidated whole cells of pathogenic and non-pathogenic Mycobacteria or Nocardia micro-organisms with a muramidase to free the immunological non-specific adjuvant,   separating the solid fraction from the mixture,   recovering the aqueous portion containing amino-acids other than those of the peptidoglycan and the immunological non-specific adjuvant, the adjuvant having reduced sensitizing action to tuberculine.   
     
     
       2. The process of claim 1 wherein the muramidase is lysozyme. 
     
     
       3. The process of claim 1 which comprises the additional step of lyophilizing the aqueous fraction containing the immunological adjuvant, thereby obtaining a water-soluble product. 
     
     
       4. The process of claim 3 which comprises the additional step of taking up the dry lyophilized extract in an aqueous solution. 
     
     
       5. The process of claim 1 which comprises, for further purification, the additional step of incubating the aqueous medium of the immunological adjuvant with a proteolytic enzyme, whereby amino-acids are removed, and separating the more purified adjuvant. 
     
     
       6. The process of claim 5 wherein the enzyme is trypsin. 
     
     
       7. The process of claim 5 in which the aqueous medium is buffered at a pH from about 7.5 to about 8.2 
     
     
       8. The process of claim 1 which comprises the additional step of filtering the aqueous solution of the immunological adjuvant on a molecular sieve and recovering the filtrate containing the more purified aqueous solution containing the immunological adjuvant. 
     
     
       9. The process of claim 8 wherein the molecular sieve is of a polydextran column. 
     
     
       10. The process of claim 9 which comprises eluting with acetic acid several fractions from the column and collecting either the first or second fraction or the second and third fraction of the aqueous filtrate corresponding to the corresponding elution peak, said fractions containing the more purified immunological adjuvant. 
     
     
       11. The process of claim 10 in which the first or second fraction of the aqueous filtrate corresponding to the first or second elution peak of the filtrate, is recovered. 
     
     
       12. The process of claim 10 in which the second or third fraction of the aqueous filtrate corresponding to the second or third elution peak of the filtrate, is recovered. 
     
     
       13. The process of claim 1 in which the immunological non-specific adjuvant contains neutral sugars, amino sugars and amino acids. 
     
     
       14. In the process for preparing a water-soluble immunological non-specific adjuvant which comprises treating an aqueous suspension of solvent-extracted delipidated whole cells of pathogenic and non-pathogenic Mycobacteria or Nocardia micro-organisms with a muramidase to free the immunological non-specific adjuvant,   separating the solid fraction from the mixture,   incubating the aqueous medium of the immunological adjuvant with a proteolytic enzyme, thereby removing amino acids, filtering the aqueous solution of the immunological adjuvant on a molecular sieve and recovering the filtrate containing the more purified aqueous solution containing the immunological adjuvant, the adjuvant having reduced sensitizing action to tuberculine.